Number

125-EN

Section

General Section

Use

Abstract

Chlorine is used as a disinfectant in swimming pools. Chlorine has the advantage of being effective against a considerable number of microorganisms. When adding free chlorine to swimming pool water, however, a very large number of unwanted chlorinated by-products are formed. Other compounds can be used for disinfection, but they are not as efficient and fast-acting as chlorine. But if e.g. silver compounds are combined with a non-chemical alternative as filtration a good result can be achieved.

Substituted substances

Alternative Substances

Reliability of information

Internet information: data are from an internet document and only a basic and partial evaluation could be performed

Reason substitution

other toxic effects
ecotoxicity
physical hazards
skin/respiratory sensitizing

Other type of alternative

Different methods for filtration, uv-technology among others.

Hazard Assessment

Substance to be substituted: Calcium hypochlorite causes severe skin burns and eye damage, is very toxic to aquatic life, may intensify fire (oxidiser) and is harmful if swallowed. Alternative substance: Hydrogen peroxide causes severe skin burns and eye damage, may cause fire or explosion (strong oxidiser), is harmful if swallowed and is harmful if inhaled. Silver (metal), iodine compounds, copper compounds and organic biocides have no harmonised classification according to Annex VI of Regulation (EC) No 1272/2008 (CLP Regulation).

Description of Substitution

The following text is an extract from the summary of the report. Chlorine is traditionally the preferred water disinfectant in swimming pools. Chlorine is effective against a considerable number of microorganisms, it reacts quickly and when dosed sufficiently it secures a lasting disinfection effect in the water. However, a very large number of unwanted chlorinated disinfection by-products (DBP) are formed when chlorine reacts with the contamination deriving from the bathers. The best known disinfection by-products are chloramines, trihalomethane (THM), halogen acetic acid (HAA) and haloacetonitriles (HAN). However a considerable number of other chlorinated organic substances are known to be formed. The existence of such by-products is a potential problem for both bathers and pool staff. Concerning alternatives hydrogen peroxide, iodine, silver- and copper compounds and organic biocides are discussed in the report. Based on the evaluation of a number of these alternative disinfectants no alternatives have been identified, which could work with the same effectiveness as chlorine. However, a more differentiated view of the risk scenario for various pool applications can open the way for application of other disinfectants, if other risk scenarios than the very fast disinfection ensured by chlorine, are given higher priority. If this is the case, testing new disinfectants should be made under controlled conditions using reference data for chlorines effect on selected microorganisms. If e.g. silver compounds are combined with a non-chemical alternative as filtration a good result can be achieved. Other compounds can be used for disinfection, but they are not as efficient and fast-acting as chlorine.

Case/substitution evaluation

Several alternatives have good disinfectant properties, but none of them is as effective as chlorine. If e.g. silver compounds are combined with a non-chemical alternative as filtration a good result can be achieved. In this case, the alternative is also has several hazardous properties , so it should be replaced by further research in the future.

State of implementation

Pilot study

Date and place of implementation

39114

Type of information supplier

User

Type of publication and availability

Freely available at http://www.mst.dk

Publication source: author, company, institute, year

Miljøstyrelsen - Danish EPA http://www.mst.dk

Publication source

Type of publication and availability

http://www2.mst.dk/Udgiv/publikationer/2007/978-87-7052-389-9/pdf/978-87-7052-390-5.pdf

Date, reviewed

December 11, 2020